// // WRP - Web Rendering Proxy // // Copyright (c) 2013-2018 Antoni Sawicki // Copyright (c) 2019 Google LLC // package main import ( "bytes" "context" "flag" "fmt" _ "image" "image/gif" "image/png" "log" "math/rand" "net/http" "net/url" "os" "strconv" "strings" "time" "github.com/chromedp/cdproto/emulation" "github.com/chromedp/cdproto/runtime" "github.com/chromedp/cdproto/cdp" "github.com/chromedp/cdproto/dom" "github.com/chromedp/chromedp" ) var ( ctx context.Context cancel context.CancelFunc gifmap = make(map[string]bytes.Buffer) ) func pageServer(out http.ResponseWriter, r *http.Request) { r.ParseForm() u := r.FormValue("url") var istr string var i bool if r.FormValue("i") == "on" { istr = "CHECKED" i = true } else { istr = "" i = false } p, _ := strconv.ParseInt(r.FormValue("p"), 10, 64) if r.FormValue("pg") == ">>" { p++ } else if r.FormValue("pg") == "<<" { p-- } else { p = 0 } w, _ := strconv.ParseInt(r.FormValue("w"), 10, 64) if w < 10 { w = 1024 } h, _ := strconv.ParseInt(r.FormValue("h"), 10, 64) if h < 10 { h = 768 } s, _ := strconv.ParseFloat(r.FormValue("s"), 64) if s < 0.1 { s = 1.0 } log.Printf("%s Page Reqest for url=\"%s\" [%s]\n", r.RemoteAddr, u, r.URL.Path) out.Header().Set("Content-Type", "text/html") fmt.Fprintf(out, "\n
\n")
if len(u) > 4 {
if strings.HasPrefix(u, "http") {
capture(u, w, h, s, p, i, out)
} else {
capture(fmt.Sprintf("http://www.google.com/search?q=%s", url.QueryEscape(u)), w, h, s, p, i, out)
}
} else {
fmt.Fprintf(out, "No URL or search query specified")
}
fmt.Fprintf(out, "\n\n")
}
func imgServer(out http.ResponseWriter, req *http.Request) {
log.Printf("%s IMG Request for %s\n", req.RemoteAddr, req.URL.Path)
gifbuf := gifmap[req.URL.Path]
defer delete(gifmap, req.URL.Path)
out.Header().Set("Content-Type", "image/gif")
out.Header().Set("Content-Length", strconv.Itoa(len(gifbuf.Bytes())))
out.Write(gifbuf.Bytes())
out.(http.Flusher).Flush()
}
func mapServer(out http.ResponseWriter, req *http.Request) {
log.Printf("%s MAP Request for %s [%v]\n", req.RemoteAddr, req.URL.Path, req.URL.Query())
}
func haltServer(out http.ResponseWriter, req *http.Request) {
log.Printf("%s Shutdown request received [%s]\n", req.RemoteAddr, req.URL.Path)
out.Header().Set("Content-Type", "text/plain")
fmt.Fprintf(out, "WRP Shutdown")
out.(http.Flusher).Flush()
cancel()
os.Exit(0)
}
func capture(gourl string, w int64, h int64, s float64, p int64, ismap bool, out http.ResponseWriter) {
var nodes []*cdp.Node
ctxx := chromedp.FromContext(ctx)
var pngbuf []byte
var gifbuf bytes.Buffer
var loc string
var res *runtime.RemoteObject
log.Printf("Processing Caputure Request for %s\n", gourl)
// Run ChromeDP Magic
err := chromedp.Run(ctx,
emulation.SetDeviceMetricsOverride(w, h, s, false),
chromedp.Navigate(gourl),
chromedp.Evaluate(fmt.Sprintf("window.scrollTo(0, %d);", p*int64(float64(h)*float64(0.9))), &res),
chromedp.Sleep(time.Second*1),
chromedp.CaptureScreenshot(&pngbuf),
chromedp.Location(&loc),
chromedp.Nodes("a", &nodes, chromedp.ByQueryAll))
if err != nil {
log.Printf("%s", err)
fmt.Fprintf(out, "
%s
", err)
return
}
log.Printf("Landed on: %s, Nodes: %d\n", loc, len(nodes))
// Process Screenshot Image
bytes.NewReader(pngbuf).Seek(0, 0)
img, err := png.Decode(bytes.NewReader(pngbuf))
if err != nil {
log.Printf("Failed to decode screenshot: %s\n", err)
fmt.Fprintf(out, "
Unable to decode page screenshot:
%s
\n", err)
return
}
gifbuf.Reset()
err = gif.Encode(&gifbuf, img, nil)
if err != nil {
log.Printf("Failed to encode GIF: %s\n", err)
fmt.Fprintf(out, "
Unable to encode GIF:
%s
\n", err)
return
}
imgpath := fmt.Sprintf("/img/%04d.gif", rand.Intn(9999))
log.Printf("Encoded GIF image: %s, Size: %dKB\n", imgpath, len(gifbuf.Bytes())/1024)
gifmap[imgpath] = gifbuf
// Process Nodes
base, _ := url.Parse(loc)
if ismap {
fmt.Fprintf(out, "", imgpath)
} else {
fmt.Fprintf(out, "\n\n")
}
out.(http.Flusher).Flush()
log.Printf("Done with caputure for %s\n", gourl)
}
func main() {
ctx, cancel = chromedp.NewContext(context.Background())
defer cancel()
var addr string
flag.StringVar(&addr, "l", ":8080", "Listen address:port, default :8080")
flag.Parse()
rand.Seed(time.Now().UnixNano())
http.HandleFunc("/", pageServer)
http.HandleFunc("/img/", imgServer)
http.HandleFunc("/map/", mapServer)
http.HandleFunc("/favicon.ico", http.NotFound)
http.HandleFunc("/halt", haltServer)
log.Printf("Starting WRP http server on %s\n", addr)
http.ListenAndServe(addr, nil)
}